package com.wl2o2o.lanqiao.xzthirteen;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Arrays;

/** 
* @author : WLei224
* @date ：2023年4月5日 上午9:13:14 
* 
*/
public class C字符统计 {
	static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
	static PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
	public static void main(String[] args) throws IOException {
		String[] string = in.readLine().trim().split("");
//		System.out.println(Arrays.toString(string));
//		System.out.println(string[0].charAt(0) - 'B');
		int[] cishu = new int[30];
		//将字母出现的次数打表放入数组中
		for(int i = 0; i < string.length; i++) {
			cishu[string[i].charAt(0) - 'A']++;
		}
		int min = 0;
		System.out.println(Arrays.toString(cishu));
		//获取到cishu中出现最多的字母
		int ans = 0;
		for(int i = 0; i < cishu.length; i++) {
			if(min <= cishu[i]) {
				min = cishu[i];
				ans = i;
			}
		}System.out.println((char)(ans + 'A'));
//		System.out.println(ans);
		
	}
}
